SYNAPTIC ORGANIZATION OF THE AUDITORY SYSTEM

我们将研究处理单声道和 在下丘（IC）的双耳信息。 为了 定义了IC中神经处理的解剖学基础， 我们将结合联合收割机轴突运输，细胞内染色， 定量方法和免疫细胞化学在光（LM）和 电子显微镜（EM）水平。 每个实验都将解决 一般假设，IC中的神经反应是一种产物， 由带状输入和特定单元定义的功能区 类型 为了确定IC的输入是否收敛以创建 在特定的功能区，两个带状输入将被标记在 同样的实验。 我们假设来自不同来源的谱带 重叠以形成功能上不同的突触域 大脑中的神经元区域 表征双耳输入的突触组织 从上级橄榄复合体（SOC），我们将使用EM 放射自显影和测试的假设，输入从SOC 可以通过它们的精细结构来识别。 我们预测这些输入 将提供最大数量的兴奋性突触（1型）， 中央核。 为了识别突触结构域的抑制性输入， 为了确定这些突触的来源，实验将联合收割机 轴突运输方法，以确定输入和 在EM水平进行免疫细胞化学以检测GABA或甘氨酸。 定量分析将检验突触 精细结构取决于神经递质。 如果多个 发现GABA或含甘氨酸的末端来源后， 可以研究IC的每个抑制性输入的结构。 最后，为了确定通过IC的功能通路， 将使用逆行标记细胞内染色方法 以识别IC中的特定细胞类型;同时， 顺行标记将用于识别特定的上行 输入到这些细胞中。 我们假设突触的内容 与特定细胞类型相关的域将创建不同的 输出通路处理听觉的不同方面 信息.

We will investigate the synaptic bases for processing monaural and binaural information in the inferior colliculus (IC). In order to define the anatomical substrates of neural processing in the IC, we will combine axonal transport, intracellular staining, quantitative methods, and immunocytochemistry at the light (LM) and electron microscopic (EM) levels. Each experiment will address the general hypothesis that neural responses in the IC are a product of functional zones defined by banded inputs and specific cell types. To determine whether the inputs to the IC converge to create specific functional zones, two banded inputs will be labeled in the same experiment. We postulate that bands from different sources overlap to form synaptic domains which are functionally distinct zones of neuropil in the IC. To characterize the synaptic organization of the binaural inputs from the superior olivary complex (SOC), we will use EM autoradiography and test the hypothesis that inputs from the SOC can be identified by their fine structure. We predict these inputs will provide the largest number of excitatory synapses (type 1) to the central nucleus. To identify the inhibitory inputs to the synaptic domains and determine the sources of these synapses, experiments will combine axonal transport methods to determine the inputs and immunocytochemistry at the EM level to detect GABA or glycine. Quantitative analyses will test the hypothesis that the synaptic fine structure depends on the neurotransmitter. If multiple sources of GABA or glycine-containing ending are found, the structure of each inhibitory input to the IC can be investigated. Finally, to define the functional pathways through the IC, retrograde labeling an intracellular staining methods will be used to identify specific cell types in the IC; simultaneously, an anterograde marker will be used to identify a specific ascending input to these cells. We postulate that the content of synaptic domains in relation to specific cell types will create distinct output pathways to process different aspects of auditory information.